Good Morning,

Many of our board designs are double sided with components on each side.
When I explained the build process, a few of the design guys expressed
concern about the 1st side seeing another reflow when the board goes through
again for the 2nd side and asked me to look into the practice of using
solder paste with different melting temperatures for the 1 st side reflowed
vs. 2nd side reflowed.  For example, use a solder paste/alloy with a higher
melting temperature for the 1st side reflowed and a lower melting
temperature for the 2nd side so the 1st side reflowed does not reflow again
(or minimize the impact on the 1st side) during 2nd side reflow.  Some of
the guys remember seeing CMs changing solder paste for the 2nd side
assembly.

Would anyone like to share their experience with this practice or comment on
its potential value.  thanks again.

joe

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------